console.log("1111");

console.log("---------------");

// var let
var i = 5;
document.write("整数：" + typeof (i) + "<br/>");
var f = 3.14;
document.write("浮点数：" + typeof (f) + "<br/>");
var str = "abc";
document.write("字符串：" + typeof (str) + "<br/>");
var c = 'a';
document.write("字符：" + typeof (c) + "<br/>");
var b = true;
document.write("布尔类型：" + typeof (b) + "<br/>");
var u;
document.write("未定义的类型：" + typeof (u) + "<br/>");
var n = null;
document.write("null：" + typeof (n) + "<br/>");

i = "a";